56121715215655 has 4 divisors (see below), whose sum is σ = 67346058258792. Its totient is φ = 44897372172520.

The previous prime is 56121715215637. The next prime is 56121715215719. The reversal of 56121715215655 is 55651251712165.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 56121715215655 - 2¹⁷ = 56121715084583 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5612171521561 + ... + 5612171521570.

It is an arithmetic number, because the mean of its divisors is an integer number (16836514564698).

Almost surely, 2^{56121715215655} is an apocalyptic number.

56121715215655 is a deficient number, since it is larger than the sum of its proper divisors (11224343043137).

56121715215655 is a wasteful number, since it uses less digits than its factorization.

56121715215655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11224343043136.

The product of its digits is 3150000, while the sum is 52.

The spelling of 56121715215655 in words is "fifty-six trillion, one hundred twenty-one billion, seven hundred fifteen million, two hundred fifteen thousand, six hundred fifty-five".